California elevator codes mention a type of elevator controller I have never heard of before.
"Preregister Operation. Operation in which signals to stop are registered in advance by buttons in the car and at the landings. At the proper point in the car travel, the operator in the car is notified by a signal (visual, audible, or otherwise) to initiate the stop, after which the landing stop is automatic."
Does anyone know more about preregister operation, and how many elevators with preregister operation still exist?
How old is the system of preregister operation? Does it predate signal control operation?
Are elevators with preregister operation car switch driven?
Do elevators with preregister operation usually have manual doors?
It sounds like the car buttons could be pushed by passengers, and not only the operator?
Unlike signal operation elevators, would there be car buttons for the terminal landings?
Would the car (and/or the hall) buttons be electromagnetically latching buttons (like the car buttons on signal operation elevators)?
What companies made preregister operation elevators?
What was the reason that the stops were initiated by the operator, and not automatically like a signal controlled elevator? Was it a limitation of the controller? Or was there a practical reason?
I am an elevator enthusiast that especially likes older elevators, and I have never even heard of this type of controller until now. I don't know of any that still exist, but it is possible a few still exist.
